@article{rosalen_rodrigues_chioderoli_brandão_siqueira_2011,  title={GPS receivers for georeferencing of spatial variability of soil attributes},  volume={31},  ISSN={0100-6916},  url={https://doi.org/10.1590/S0100-69162011000600013},  DOI={10.1590/S0100-69162011000600013},  number={6},  journal={Engenharia Agrícola},  publisher={Associação Brasileira de Engenharia Agrícola},  author={Rosalen, David L and Rodrigues, Marcos S and Chioderoli, Carlos A and Brandão, Flavia J. C and Siqueira, Diego S},  year={2011},  month={Dec},  pages={1162–1169} }